4 8 



The Encep/iti/on 



Above, the ascending parietal convolution inclines backwards and 

 ends in the superior parietal lobule, which is continuous on the mesial 

 surface of the hemisphere with the quadrate lobule which is just 

 behind the para-central lobule (p. 53). That part of the parietal lobe 

 which is above the end of the horizontal limb of the Sylvian fissure is 

 the supra-marginal lobule, and that which is just behind the ending is 

 the angular lobule. The former is covered by the parietal eminence. 



The occipital lobe rests on the tentorium and is indistinctly mapped 

 into three horizontal lobules, called first, second, and third. This lobe 

 is continued into the parietal and temporo-sphenoidal lobes by four 

 small annectant convolutions. 



The temporo-sphenoidal lobe lies in the middle fossa of the base of 

 the skull. It is limited above by the Sylvian fissure, and is mapped 



fis-.Ro. 



The Motor Area, after GOWEKS. 



into first, second, and third convolutions (numbered from above down- 

 wards) by two antero-posterior fissures, the upper of which lies a little 

 below, and parallel with the horizontal limb of the Sylvian fissure. 

 Hence the upper furrow is called the paralle I fissure. 



The motor area comprises the hinder part of the three frontal 

 convolutions, the convolutions bounding the fissure of Rolando, viz., 

 ascending frontal and ascending parietal ; the continuation of the 

 latter into the superior parietal lobule ; and that part of the marginal 

 convolution which lies in front of the quadrate lobe the para-central 

 lobe. This last-named lobe is formed where the ascending frontal and 

 parietal lobes blend above to prevent the fissure of Rolando entering 

 the longitudinal fissure. The whole of this area is supplied by the 

 middle cerebral artery (p. 42). 



That part of the frontal lobe which lies in front of the coronal 



